Restoration guide - key steps to effective management...animals, vermin and their predators. Wild...
Transcript of Restoration guide - key steps to effective management...animals, vermin and their predators. Wild...
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3. Key steps to effectivemanagement
In this guidebook, �management� means any action taken to prevent or reduce
further degradation of native ecosystems. The purpose of management is to
encourage natural processes (like plant regeneration and succession) and control
weeds and pests that interfere with these processes. You should nearly always
protect and manage natural ecosystems (sections 3 & 4) as a priority, before
attempting restoration (sections 5 to 10).
MANAGEMENT PLANS
A management plan (or checklist) helps ensure you address important issues and
follow a clear course of action. You should prepare a detailed management plan for
large protected areas or those that are publicly funded. For others a simple checklist
may be adequate. If the area is to be legally protected, you may have to follow a formal
process.
Ensure that your management plan includes the following actions. It should:
� Describe the remnant, its natural resources, and their importance (e.g., main
communities and species, landforms and water bodies).
� Outline any management issues or threats.
� State the goals or aims of protection. These should be realistic and
straightforward, e.g. Protect the (specified) forest remnant and ensure it is
self-sustaining.
� State objectives that identify what management results are sought for specific
issues or threats, e.g. Identify the factors limiting natural regeneration, and
take action to restore this process.
• Detail methods that describe how the objectives will be tackled and in what
time frame, e.g. Erect post and wire fences to exclude stock, and hand removal
of weeds within 6 months.
• Specify monitoring methods for assessing the effects of management actions or
natural change.
• Indicate how you will adapt management actions in response to assessment.
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SITE ASSESSMENT
Clarifying an area�s ecological values and importance will help justify its protection,
and provide background information for use in your management plan. It will also
help you identify threats to the ecosystem, and where there are restoration needs.
Depending on the size or complexity of the ecosystem and the level of protection/
funding being sought, you may need specialist advice or assistance.
Your site assessment should:
• Describe the main plant/animal communities, and their condition.
• List the main and any threatened native plants and animals.
• Describe the main landforms, such as river terraces, fans, ridges and slopes.
• Identify water bodies and drainage patterns, including wetlands, creeks and
damp areas.
• Identify factors affecting the ecosystem, such as aspect, wind exposure, frost,
drains, weeds, animal pests and grazing.
WEED CONTROL
Although many introduced plants do not cause problems in natural ecosystems,
invasive weeds can limit the regeneration or retention of native plants and animals.
Weeds may be herbs, shrubs, vines or trees. They typically invade open or disturbed
sites, which are often found in remnant ecosystems. You will nearly always need to
control weeds, as they compete for light, space, moisture and nutrients. You have a
legislative obligation to control or eradicate weeds identified in your local Regional
Pest Management Strategy.
Key management guidelines
• Prepare a weed management strategy so that weed control is done logically and
efficiently.
• Assess whether weeds really are a problem, or whether attempted control will
only make matters worse.
• Identify and eliminate weed sources within remnants and from adjacent lands,
and reduce open areas that could be invaded by weeds (Porteous 1993).
• Tackle weed control promptly, or the task may get out of hand (�one years
seeding, seven years weeding�).
• Avoid over-clearing weeds where control could cause disturbance, weed re-
establishment or openings for new weeds, e.g., willow removal resulting in
blackberry spread.
� Minimise the use of herbicides by using other weed control methods as much
as possible.
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Weed control methods
� Shading - dense planting shades out some weeds and limits their
establishment.
� Hand weeding - labour intensive, but suitable for specific weeds, fragile
sites or low levels of infestation. Hard to kill weeds should be removed from
the site (Porteous 1993).
� Ring barking - woody weeds with large stems or trunks (Porteous 1993)
� Mechanical weeding - e.g. the use of weedeaters and rotary slashers.
� Controlled grazing - based on carefully applied adaptive management.
� Biocontrol - introducing biological agents, such as fungi or insects to
control specific weeds, e.g. gorse, spider mite.
� Herbicide use - applied to cut stumps, sprayed onto leaves, injected into
the trunk or applied to frills around a trunk (Porteous 1993).
Caution
Poorly managed weed control is a major cause of native plant death.
� Weedeaters can ring-bark planted trees.
� Grubbing can damage sensitive roots.
� Native plants are sensitive to herbicides, especially podocarps. Spray drift
can easily destroy an expensive plant, wasting time, effort, and money.
Inadvertent spray damage to kahikatea is expensive in direct costs, lost time and
lowered morale.
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ANIMAL PEST CONTROL
Originally New Zealand had no land-
based mammal predators or
browsers, but human settlement
inroduced domestic stock, game
animals, vermin and their predators.
Wild animals and animal pests are
defined by statute, but they are all
termed �animal pests� in this
guidebook. They include mice, rats,
stoats, rabbits, hares, goats, pigs,
deer, possums, cats and introduced
insects such as wasps. All these need
controlling as they eat foliage, fruits
and seeds, compete with native
animals for food (or eat them as food)
and alter ecological processes. You
have a legislative obligation to control
animal pests identified in your local
Regional Pest Management Strategy.
Sometimes you will need to co-
ordinate any control efforts with
adjacent landholders. This is
particularly important for large sites
and often involves working with
regional councils, DOC and Landcare groups.
Key management guidelines:
• Prepare an animal pest management strategy, so control is done logically and
efficiently.
• Identify which pests are problems, and what control methods should be used.
• Identify possible prey switching that might occur, e.g. increased predation on
native birds when rabbit numbers are reduced.
� Undertake control promptly before pest numbers build up.
• Work co-operatively with neighbours and other managers if appropriate.
• Beware of all health, safety and environmental impacts associated with animal
control
Rabbit damaged tussocks and matagouri.
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Animal control methods
� Poisoning, shooting and trapping - need to avoid killing non-target
species.
� Fencing - excludes some animal pests, and can be cost-effective, e.g. rabbit
netting.
� Shields - to deter possums; moats around wetlands - to reduce pest access.
� Creating less suitable conditions - such as increasing vegetation cover
and moisture to deter rabbits.
� Biocontrol - using biological agents to control pests, e.g. parasitoid wasps
on wasps.
� Integrated pest management - a combination of these methods, often
used in special areas subjected to intensive pest control, e.g. DOC's
'mainland islands'.
Excluding stock and wild animals from this mountain beech/tawhai forest in the mid
Canterbury foothills has resulted in the regeneration of palatable understorey species.
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DOMESTIC STOCK
Domestic stock include sheep, cattle, goats, deer and any other farmed animals. Their
impacts include grazing or browsing native vegetation, preventing plant
regeneration, altering soil and water nutrient levels, compacting soil and spreading
weeds. Stock must be excluded from forests and most other protected areas.
However, controlled grazing may be used to maintain biodiversity in some induced
shrublands and grasslands (see section 4).
Stock control methods
� Fencing - needs to be appropriate for the type of stock and be regularly
maintained.
� Repellents - realistically an option only where plants are small, e.g.
restoration plantings.
� Co-operation between adjacent landholders - can reduce stock access,
but no substitute for secure fencing.
Pïngao remnant nearly destroyed by cattle.
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Caution
Fences are your only realistic option for excluding stock.
The most elaborate fences, such as those at
Karori Wildlife Sanctuary, exclude all land
animal pests and stock. A single-strand electric
fence may be sufficient to keep cattle out, as
long as you check it frequently. Environment
Waikato has information about a cheaper
predator-proof fence suitable for use by private
landowners.
BUFFERING
You can establish a buffer zone or area around a
remnant and manage it to limit adverse effects
from adjacent land uses. Buffers may take the
form of a shrubby border, which also provides
new habitat and increases local species
diversity. Specific benefits include:
• Reducing fire risk.
• Reducing risk of spray damage.
• Protecting forest edges from wind penetration and weed ingress.
• Protecting sensitive plants and animals in the interior.
• Limiting input of sediments and nutrients (particularly in wetlands and riparian
areas), and introduced plant seeds.
MONITORING
Monitoring measures the success of a project in terms of its stated goals and
objectives. Whatever monitoring methods you use, they should be as simple as
possible (Atkinson 1994), standardised and repeatable.
Formal scientific monitoring is appropriate for large-scale, publicly funded projects.
Professional advice will ensure a more reliable evaluation and interpretation of
habitat changes. For most small projects, it is enough to take photographs from fixed
points at the beginning, and then at regular intervals (e.g. annually). Record the date
on them, and choose views that will not be grown out.
A demonstration section of the predator fence
at the Karori sanctuary, Wellington. This
elaborate fence even excludes mice and is also
able to withstand human sabotage.
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For more elaborate monitoring you need to use several indicators sensitive to various
kinds of change. Indicators that can be measured include:
• Spread or incidence of weeds.
• Damage caused by stock grazing or animal pests.
• Changes in regeneration patterns after fencing.
• Build-up of forest litter.
• Cover of ferns, mosses and lichens, as an indicator of microhabitat
development.
• Bird and invertebrate records as indicators of increasing diversity.
Monitoring methods
• Fixed sample plots to measure changes in plant species presence, density
and regeneration.
• Photopoints to provide a picture of ecological changes, such as plants
regenerating after animal pests have been excluded.
• Fixed sample plots to measure changes in abundance of pests and weeds
(trapping, pellet counts, cover and density).
• Standardised observations of bird numbers and species (such as 5-minute
counts) or sampling of invertebrates (transects and pitfall traps).
Once you have achieved the initial desired vegetation structure, the simplest
measures of sustainability are regeneration and resistance to weeds.
Further reading
An illustrated guide to common weeds of New Zealand. Roy B, Popay I, Champion P,
James T and Rahman A 1998. [Book � photographs and descriptions of a wide
variety of weeds. A number of native plants are listed as weeds, but little
explanation is given for their selection. We do not think they should be
described as weeds]
Christchurch waterway maintenance plant guide. Weeds, and how to tell them from
similar looking plants. McCombs K, Meurk C and Morland K 1999. [Book,
available on request from Christchurch City Council � contains clear
photographs and descriptions for easy plant identification]
Ecology and management of invasive weeds. Williams PA 1997. [Book � provides in-
depth information about weed life forms, dispersal, vegetation succession
and weed control]
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Gully restoration guide. A guide to assist in the ecological restoration of Hamilton�s
gully systems. Wall K and Clarkson B 2001. [Booklet � a step by step guidebook
on gully restoration. Includes a gully profile, information on soils, native
plants to use, and weed identification and control]
Native forest monitoring. A guide for forest owners and managers. Handford P 2000.
[Book � provides detailed information on methods, fieldwork, data analysis,
indicators of forest health, and the level of skill and precision needed for the
methods used]
Native forest restoration. A practical guide for landowners. Porteous T 1993. [Book �
comprehensive coverage of managing remnants, with detailed restoration
techniques]
New Zealand�s wetlands. A management guide. Buxton R 1991. [Book � describes
different types of wetlands and their functioning, and provides management
and restoration guidelines and summaries]